[PATCH v3 2/2] rtc: ds1307: Add support for Epson RX8111

Mike Looijmans
2022-11-07T09:51:26Z

The rx_8111 is quite similar to the rx_8030. This adds support for this
chip to the ds1307 driver. Date/time and alarm registers are in the
usual places. The nvmem is located at 0x40. Time stamping is not
supported.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>

---

Changes in v3:
Wrong version of code sent in v2
Attempt to fix e-mail sending issues

Changes in v2:
Add "_REG" in register names
Add interrupt/alarm handling (different from rx8030)

drivers/rtc/rtc-ds1307.c | 306 ++++++++++++++++++++++++++++++++++++---
1 file changed, 284 insertions(+), 22 deletions(-)

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index d51565bcc189..5aeb5732bae5 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -46,6 +46,7 @@ enum ds_type {
m41t11,
mcp794xx,
rx_8025,
+ rx_8111,
rx_8130,
last_ds_type /* always last */
/* rs5c372 too? different address... */
@@ -113,6 +114,24 @@ enum ds_type {
# define RX8025_BIT_VDET 0x40
# define RX8025_BIT_XST 0x20

+#define RX8111_REG_EXTENSION 0x1d
+# define RX8111_REG_EXTENSION_WADA BIT(3)
+#define RX8111_REG_FLAG 0x1e
+# define RX8111_REG_FLAG_VLF BIT(1)
+# define RX8111_REG_FLAG_EVF BIT(2)
+# define RX8111_REG_FLAG_AF BIT(3)
+# define RX8111_REG_FLAG_TF BIT(4)
+# define RX8111_REG_FLAG_UF BIT(5)
+#define RX8111_REG_CONTROL 0x1e
+# define RX8111_REG_CONTROL_EIE BIT(2)
+# define RX8111_REG_CONTROL_AIE BIT(3)
+# define RX8111_REG_CONTROL_TIE BIT(4)
+# define RX8111_REG_CONTROL_UIE BIT(5)
+#define RX8111_REG_PWR_SWITCH_CTRL 0x32
+# define RX8111_PSC_SMP_INIEN BIT(6)
+# define RX8111_PSC_SMP_CHGEN BIT(7)
+#define RX8111_REG_TIME_STAMP_BUF_CTRL 0x34
+
#define RX8130_REG_ALARM_MIN 0x17
#define RX8130_REG_ALARM_HOUR 0x18
#define RX8130_REG_ALARM_WEEK_OR_DAY 0x19
@@ -205,6 +224,68 @@ struct chip_desc {

static const struct chip_desc chips[last_ds_type];

+static int ds1307_check_voltage_lost(struct ds1307 *ds1307)
+{
+ int ret;
+ unsigned int reg;
+ unsigned int mask;
+ unsigned int regflag;
+
+ switch (ds1307->type) {
+ case rx_8111:
+ reg = RX8111_REG_FLAG;
+ mask = RX8111_REG_FLAG_VLF;
+ break;
+ case rx_8130:
+ reg = RX8130_REG_FLAG;
+ mask = RX8130_REG_FLAG_VLF;
+ break;
+ default:
+ return 0;
+ }
+
+ ret = regmap_read(ds1307->regmap, reg, &regflag);
+ if (ret) {
+ dev_err(ds1307->dev, "%s error %d\n", "read", ret);
+ return ret;
+ }
+
+ if (regflag & mask) {
+ dev_warn_once(ds1307->dev, "oscillator failed, set time!\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int ds1307_clear_voltage_lost(struct ds1307 *ds1307)
+{
+ int ret;
+ unsigned int reg;
+ unsigned int mask;
+
+ switch (ds1307->type) {
+ case rx_8111:
+ reg = RX8111_REG_FLAG;
+ mask = (unsigned int)~RX8111_REG_FLAG_VLF;
+ break;
+ case rx_8130:
+ reg = RX8130_REG_FLAG;
+ mask = (unsigned int)~RX8130_REG_FLAG_VLF;
+ break;
+ default:
+ return 0;
+ }
+
+ ret = regmap_write(ds1307->regmap, reg, mask);
+ if (ret) {
+ dev_err(ds1307->dev, "%s error %d\n", "write", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
static int ds1307_get_time(struct device *dev, struct rtc_time *t)
{
struct ds1307 *ds1307 = dev_get_drvdata(dev);
@@ -212,19 +293,9 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
const struct chip_desc *chip = &chips[ds1307->type];
u8 regs[7];

- if (ds1307->type == rx_8130) {
- unsigned int regflag;
- ret = regmap_read(ds1307->regmap, RX8130_REG_FLAG, &regflag);
- if (ret) {
- dev_err(dev, "%s error %d\n", "read", ret);
- return ret;
- }
-
- if (regflag & RX8130_REG_FLAG_VLF) {
- dev_warn_once(dev, "oscillator failed, set time!\n");
- return -EINVAL;
- }
- }
+ ret = ds1307_check_voltage_lost(ds1307);
+ if (ret)
+ return ret;

/* read the RTC date and time registers all at once */
ret = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
@@ -397,15 +468,9 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
return result;
}

- if (ds1307->type == rx_8130) {
- /* clear Voltage Loss Flag as data is available now */
- result = regmap_write(ds1307->regmap, RX8130_REG_FLAG,
- ~(u8)RX8130_REG_FLAG_VLF);
- if (result) {
- dev_err(dev, "%s error %d\n", "write", result);
- return result;
- }
- }
+ result = ds1307_clear_voltage_lost(ds1307);
+ if (result)
+ return result;

return 0;
}
@@ -541,6 +606,174 @@ static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307, u32 ohms, bool diode)
return setup;
}

+static u8 do_trickle_setup_rx8111(struct ds1307 *ds1307, u32 ohms, bool diode)
+{
+ /* make sure that the backup battery is enabled */
+ u8 setup = RX8111_PSC_SMP_INIEN;
+
+ if (diode)
+ setup |= RX8111_PSC_SMP_CHGEN;
+
+ return setup;
+}
+
+static irqreturn_t rx8111_irq(int irq, void *dev_id)
+{
+ struct ds1307 *ds1307 = dev_id;
+ irqreturn_t result = IRQ_NONE;
+ int ret;
+ u8 ctl[2];
+ u8 flags = 0;
+
+ rtc_lock(ds1307->rtc);
+
+ /* Read flag and control registers. */
+ ret = regmap_bulk_read(ds1307->regmap, RX8111_REG_FLAG, ctl,
+ sizeof(ctl));
+ if (ret < 0)
+ goto out;
+
+ if (ctl[0] & RX8111_REG_FLAG_AF) {
+ result = IRQ_HANDLED;
+ flags |= RTC_AF; /* Alarm */
+ ctl[1] &= ~RX8111_REG_CONTROL_AIE;
+ }
+ /*
+ * If an interrupt occurred that we cannot process, we'll have to turn
+ * it off, otherwise we'd be called again and again.
+ */
+ if (ctl[0] & RX8111_REG_FLAG_UF) {
+ result = IRQ_HANDLED;
+ ctl[1] &= ~RX8111_REG_CONTROL_UIE;
+ }
+ if (ctl[0] & RX8111_REG_FLAG_TF) {
+ result = IRQ_HANDLED;
+ ctl[1] &= ~RX8111_REG_CONTROL_TIE;
+ }
+ if (ctl[0] & RX8111_REG_FLAG_EVF) {
+ result = IRQ_HANDLED;
+ ctl[1] &= ~RX8111_REG_CONTROL_EIE;
+ }
+ /* Clear all flags */
+ ctl[0] &= ~(RX8111_REG_FLAG_UF | RX8111_REG_FLAG_TF |
+ RX8111_REG_FLAG_AF | RX8111_REG_FLAG_EVF);
+
+ ret = regmap_bulk_write(ds1307->regmap, RX8111_REG_FLAG, ctl,
+ sizeof(ctl));
+ if (ret < 0)
+ goto out;
+
+ rtc_update_irq(ds1307->rtc, 1, flags | RTC_IRQF);
+
+out:
+ rtc_unlock(ds1307->rtc);
+
+ return result;
+}
+
+static int rx8111_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct ds1307 *ds1307 = dev_get_drvdata(dev);
+ u8 ald[3], ctl[2];
+ int ret;
+
+ /* Read alarm registers. */
+ ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_ALARM_MIN, ald,
+ sizeof(ald));
+ if (ret < 0)
+ return ret;
+
+ /* Read flag and control registers. */
+ ret = regmap_bulk_read(ds1307->regmap, RX8111_REG_FLAG, ctl,
+ sizeof(ctl));
+ if (ret < 0)
+ return ret;
+
+ t->enabled = !!(ctl[1] & RX8111_REG_CONTROL_AIE);
+ t->pending = !!(ctl[0] & RX8111_REG_FLAG_AF);
+
+ /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
+ t->time.tm_sec = -1;
+ t->time.tm_min = bcd2bin(ald[0] & 0x7f);
+ t->time.tm_hour = bcd2bin(ald[1] & 0x7f);
+ t->time.tm_wday = -1;
+ t->time.tm_mday = bcd2bin(ald[2] & 0x7f);
+ t->time.tm_mon = -1;
+ t->time.tm_year = -1;
+ t->time.tm_yday = -1;
+ t->time.tm_isdst = -1;
+
+ dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d enabled=%d\n",
+ __func__, t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
+ t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled);
+
+ return 0;
+}
+
+static int rx8111_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct ds1307 *ds1307 = dev_get_drvdata(dev);
+ u8 ald[3], ctl[3];
+ int ret;
+
+ dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
+ "enabled=%d pending=%d\n", __func__,
+ t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
+ t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
+ t->enabled, t->pending);
+
+ /* Read control registers. */
+ ret = regmap_bulk_read(ds1307->regmap, RX8111_REG_EXTENSION, ctl,
+ sizeof(ctl));
+ if (ret < 0)
+ return ret;
+
+ ctl[0] &= RX8111_REG_EXTENSION_WADA;
+ ctl[1] &= ~RX8111_REG_FLAG_AF;
+ ctl[2] &= ~RX8111_REG_CONTROL_AIE;
+
+ ret = regmap_bulk_write(ds1307->regmap, RX8111_REG_EXTENSION, ctl,
+ sizeof(ctl));
+ if (ret < 0)
+ return ret;
+
+ /* Hardware alarm precision is 1 minute! */
+ ald[0] = bin2bcd(t->time.tm_min);
+ ald[1] = bin2bcd(t->time.tm_hour);
+ ald[2] = bin2bcd(t->time.tm_mday);
+
+ ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_ALARM_MIN, ald,
+ sizeof(ald));
+ if (ret < 0)
+ return ret;
+
+ if (!t->enabled)
+ return 0;
+
+ ctl[2] |= RX8111_REG_CONTROL_AIE;
+
+ return regmap_write(ds1307->regmap, RX8111_REG_CONTROL, ctl[2]);
+}
+
+static int rx8111_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct ds1307 *ds1307 = dev_get_drvdata(dev);
+ int ret, reg;
+
+ ret = regmap_read(ds1307->regmap, RX8111_REG_CONTROL, &reg);
+ if (ret < 0)
+ return ret;
+
+ if (enabled)
+ reg |= RX8111_REG_CONTROL_AIE;
+ else
+ reg &= ~RX8111_REG_CONTROL_AIE;
+
+ dev_dbg(dev, "%s, enable=%u, reg=0x%x\n", __func__, enabled, reg);
+
+ return regmap_write(ds1307->regmap, RX8111_REG_CONTROL, reg);
+}
+
static u8 do_trickle_setup_rx8130(struct ds1307 *ds1307, u32 ohms, bool diode)
{
/* make sure that the backup battery is enabled */
@@ -943,6 +1176,14 @@ static const struct rtc_class_ops rx8130_rtc_ops = {
.alarm_irq_enable = rx8130_alarm_irq_enable,
};

+static const struct rtc_class_ops rx8111_rtc_ops = {
+ .read_time = ds1307_get_time,
+ .set_time = ds1307_set_time,
+ .read_alarm = rx8111_read_alarm,
+ .set_alarm = rx8111_set_alarm,
+ .alarm_irq_enable = rx8111_alarm_irq_enable,
+};
+
static const struct rtc_class_ops mcp794xx_rtc_ops = {
.read_time = ds1307_get_time,
.set_time = ds1307_set_time,
@@ -1012,6 +1253,16 @@ static const struct chip_desc chips[last_ds_type] = {
.century_bit = DS1337_BIT_CENTURY,
.bbsqi_bit = DS3231_BIT_BBSQW,
},
+ [rx_8111] = {
+ .alarm = 1,
+ .nvram_offset = 0x40,
+ .nvram_size = 0x40, /* 0x40 .. 0x7F is user RAM */
+ .offset = 0x10,
+ .irq_handler = rx8111_irq,
+ .rtc_ops = &rx8111_rtc_ops,
+ .trickle_charger_reg = RX8111_REG_PWR_SWITCH_CTRL,
+ .do_trickle_setup = &do_trickle_setup_rx8111,
+ },
[rx_8130] = {
.alarm = 1,
/* this is battery backed SRAM */
@@ -1063,6 +1314,7 @@ static const struct i2c_device_id ds1307_id[] = {
{ "pt7c4338", ds_1307 },
{ "rx8025", rx_8025 },
{ "isl12057", ds_1337 },
+ { "rx8111", rx_8111 },
{ "rx8130", rx_8130 },
{ }
};
@@ -1137,6 +1389,10 @@ static const struct of_device_id ds1307_of_match[] = {
.compatible = "isil,isl12057",
.data = (void *)ds_1337
},
+ {
+ .compatible = "epson,rx8111",
+ .data = (void *)rx_8111
+ },
{
.compatible = "epson,rx8130",
.data = (void *)rx_8130
@@ -1880,6 +2136,12 @@ static int ds1307_probe(struct i2c_client *client,
DS1307_REG_HOUR << 4 | 0x08, hour);
}
break;
+ case rx_8111:
+ /* Use memory as user RAM */
+ regmap_write(ds1307->regmap, RX8111_REG_TIME_STAMP_BUF_CTRL, 0);
+ /* Disable timer, events, frequency output */
+ regmap_write(ds1307->regmap, RX8111_REG_EXTENSION, 0xc8);
+ break;
case ds_1388:
err = regmap_read(ds1307->regmap, DS1388_REG_CONTROL, &tmp);
if (err) {
--
2.17.1